News 17 Jul 2019

Let’s talk acidity

17 Jul 2019
#Coffee Beans #Coffee brewing #Pour-over

Let’s talk acidity

Written by:
Dušan Matičič, head roaster at GOAT STORY

Some like it, some don't. Acidity. What to do if you have a bag of coffee that is waaay too acidic for your taste? Can you mute that vibrancy in your pour over? You can. But the process is not as simple as turning down the volume knob ...

We have been testing a lot of coffees lately and our test process is usually quite extensive. First, we brew each coffee for our core coffee team. Our taste in coffee has changed over the years, starting from commodity coffee, learning about specialty, and origin in coffee. It’s quite logical that we learned to love the variety of flavors in a cup. And thus, learning to love what acidity can bring to the flavor. Don’t get us wrong – we’re not talking about the sharp and unpleasant sour flavor. We’re talking about the smooth acidity but the kind you may find in fruit and wine. The good acidity. The tasty acidity.

The next step in the evaluation of coffee is offering coffee to the rest of our team. Being used to milk-based espresso drinks, these girls and boys are the perfect test team. And especially when it comes to coffees with a lot of acidities, the common feedback is that acidity is the only thing they can taste. It’s simply not their cup of choice.

Of course, there are also our random “coffee tasters”, people who come to visit and like to enjoy a nice cup of coffee while they are here. They are used to the fact that they will not get a conformist commodity cup of coffee over here. And most like the fact that they can get a bit experimental about coffee. But again – the feedback on acidity in coffee is, apart from those who are used to a cup with more acidity, mostly negative.


You can fine-tune the acidity in your coffee by changing the way your brew coffee as well. GINA coffee brewer's precision valve makes it possible. 


So what’s the deal with acidity in coffee?

From our experience, people mostly hate it. At first. But then again, most people hate the taste of olives when they first try them. But I know many that are now in love with the briny, bitter, and slightly acidic taste of those little things.

This brings us to something we know as an acquired taste. Coffee itself, even in its most basic commodity form is a love it or hate it affair. But still, some simply learn to love the taste. And then you have specialty coffees, single origins, roasted carefully to preserve and enhance the flavors. For a commodity coffee lover, it can be a shocking experience. You love it or hate it. But the point is, you can get used to the flavor and learn to appreciate it and never look back (you probably know the feeling if you’re reading this).

Bottom line is, when talking about specialty coffee, acidity is a good thing. But sometimes you get hold of a bag of beans that are just too much for you and want to tone down that acidity.

Can it be done? Yes. Somewhat. Let’s see how.


Know your beans

Okay, many coffees in the world will have a good amount of acidity. Farmers do their best to process the beans in a way to preserve or even enhance the acidity found in the bean and the roasters do their part to balance the flavors and make the acidity work hand in hand with other flavors in the bean.

Of course, there are beans that will have more acidity and those who have less. Learn to choose the beans you like by asking a couple of questions:


Are the beans hard or soft?

Harder beans (the ones with more density that is) grow at a higher altitude (or in general in a cooler environment) and thus grow slower. The result is more fruity flavors and more acidity.


How was the coffee processed

There are three basic processing methods (oh my, don’t get us started on the variations and fermentations please): wet (washed), natural (dry), and honey (pulped natural). We won’t dive into details, but keep in mind that processing impacts the flavor. Naturals and honey processed coffees tend to have more sweetness and body. Washed coffees lean towards a clean coffee flavor that enhances the complex acidity in coffee. If you’re not a fan of acidity, stay away from washed coffees (but as with everything in coffee, don’t take this as a golden rule).


The water factor

Let’s face it – your cup of coffee is mostly water (about 96%, give or take a few %). That means that water influences the flavor of coffee bigtime! But how?

Hard water (one that contains more minerals like magnesium and calcium) can act as a buffer for acidity and lower the perception of acids in coffee.

Soft water (with low mineral content) is usually richer in sodium and that will enhance the perception of acidity in coffee.

Play with water, maybe use a water supplement for coffee brewing or filtered water and compare results. You might be surprised how it affects your cup!



Extraction is, at its core, a simple process – mixing coffee and water to diffuse the components that hold flavor and aroma in coffee into the water. Sounds easy, right?

It’s not.

How much coffee? How much water? How long? What grind setting? What water temperature? What brewing device? And the list goes on …

For the sake of clarity, we’ll focus on pour over brewing, as it enables easy modification to the extraction (meaning you can easily tweak the brew).

Let’s dig into basics … When you start the extraction of coffee, the first thing you will get out of coffee is the acids. A short time will thus create a cup with high acidity that sticks out. Later in the extraction comes sweetness that balances the acidity along with more body for a fuller mouthfeel. If you overdo the extraction, you’ll be punished with bitterness as water starts to extract the flavors of the fibers that hold the bean together. And as those are cellulose and similar, they really don’t taste very good.

This is a basic explanation of extraction. It doesn’t just create “strong” or “weak” coffee. If you focus on extraction a bit more, you’ll be able to control how your coffee will taste. Nice, huh?


Controlling extraction

There is no one recipe on how to control your extraction. It’s a combination of things.


A coarser grind will speed up your brew time but slow down the extraction. Whay? Bigger chunks of coffee take more time to extract all the flavors. If your brew time is short, you’ll probably get a more acidic coffee that will lack the sweetness and body (remember the bit about acids being extracted first, right?). For more acidity in your cup, grind coarser. For less acidity grind finer. But don’t overdo it, fine grinds mean a speedy extraction and you can end up with a bitter cup. Try a few grind settings.


Most roasters will tell you the roast level (light, medium, dark) so you can get the idea about what you’re drinking. It’s not just about color but about solubility (the longer the roast, the more soluble the coffee). Keep in mind that lighter roasted coffee is less soluble than darker roasted coffee. That means that lighter roasts extract slower, darker roasts extract quicker.


We already covered the hard Vs. soft water thing. If you can not control that, you can surely control water temperature. Rule of thumb is that lower water temperature will extract the coffee slower. And vice-versa: a higher temperature will speed up the extraction. BUT, a temperature that is too low can not extract all the compounds in coffee (think cold brew, where acidity is muted).

If you’re aiming for lower acidity in coffee, go for a lower temperature (90 – 91 degrees Celsius) with a longer extraction time. For a more vibrant cup with pronounced acidity, brew quick and hot (up to 94 – 96 degrees Celsius).


Bottom line

There is no one-for-all recipe to tune down acidity in your coffee. But you can play with your pour over and adjust one setting at a time and track results. Slowly but surely you will understand your extraction and find your sweet spot and general rules to follow for all your coffees. Good luck and let us know how you’re doing! We would love to hear from you!